Thanks for the great ideas and your thoughts and suggestions! We feel more comfortable taking Oreo with us now after reading all these wonderful ideas.
Oreo travels OK but every now and then he does get "vocal" but we think that's Oreo being Oreo as he's pretty vocal around the house as well.
Our plan is to take an extended lunch break at a rest area of whatever and give him time in the trailer, hopefully he'll get the idea and do his business while we're on break. We don't plan on traveling more than 400 miles a day and definitely not into the late hours of the evening.
Thanks again for your ideas.
Dan